Appropriate use of drug-eluting stents: balancing the reduction in restenosis with the concern of late thrombosis

Case‐fatality rate of major bleeding events in patients on dual antiplatelet therapy after percutaneous coronary intervention: A systematic review and meta‐analysis

Background

Assessment of the case-fatality rate (CFR) of major bleeding on dual antiplatelet therapy (DAPT) may improve balancing risks and benefits of different durations of DAPT following percutaneous coronary intervention (PCI).

Objectives

To determine the CFR of major bleeding in patients on DAPT after PCI and to compare rates among different durations of DAPT.

Methods

Medline, Embase, and CENTRAL were searched from inception to August 2021 for randomized trials that reported fatal bleeding among patients who were randomized to ≥1 month of DAPT following PCI. Summary estimates for CFRs of major bleeding were calculated using the random-effects inverse-variance method. Statistical heterogeneity was evaluated using the I ² statistic.

Results

Of 2777 citations obtained by the search, 15 (48%) of 31 potentially eligible studies were excluded because fatal bleeding was not reported, leaving 16 studies that were included in the analysis. Overall, there were 823 major bleeding events including 91 fatal events in 48,884 patients who were assigned to receive DAPT during study follow-up. The CFR of major bleeding was 10.8% (95% confidence interval [CI], 7.1-16.2; I ² = 50%) in the entire study population, and 13.8% (95% CI, 6.5-27.1; I ² = 28%), 11.2% (95% CI, 6.7-18.0; I ² = 0%), and 5.8% (95% CI, 3.0-11.1; I ² = 0%) in those on short-term (≤6 months; n = 16,553), standard-term (12 months; n = 19,453), and long-term DAPT (>12 months; n = 10,238), respectively.

Conclusion

Fatal bleeding is not reported in many studies evaluating DAPT after PCI. The CFR of major bleeding on DAPT is substantial and may be higher in the first 12 months of DAPT than during long-term DAPT.

The Predictive Value of the Perivascular Adipose Tissue CT Fat Attenuation Index for Coronary In-stent Restenosis

Objectives

To investigate the association between the perivascular adipose tissue (PVAT) fat attenuation index (FAI) derived from coronary computed tomography angiography (CCTA) and the prevalence of in-stent restenosis (ISR) in patients with coronary stent implantation.

Methods

A total of 117 patients with previous coronary stenting referred for invasive coronary angiography (ICA) were enrolled in this retrospective observational analysis. All patients underwent CCTA between July 2016 and November 2021. The deep learning-based (DL-based) method was used to analyze and measure the peri-stent FAI value. Additionally, the relationship between hematological and biochemical parameters collected from all the patients was also explored. The least absolute shrinkage and selection operator (LASSO) method was applied to the most useful feature selection, and binary logistic regression was used to test the association between the selected features and ISR. The predictive performance for ISR of the identified subgroups was evaluated by calculating the area under the curve (AUC) of receiver operator curves plotted for each model. The Pearson correlation coefficient was used to assess the correlation of peri-stent FAI values with degrees of ISR.

Results

The peri-stent FAI values in the ISR group were significantly higher than those in the non-ISR group (−78.1 ± 6.2 HU vs. −87.2 ± 7.3 HU, p < 0.001). The predictive ISR features based on the LASSO analysis were peri-stent FAI, high-density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (ApoA1), and high-sensitivity c-reactive protein (hs-CRP), with an AUC of 0.849, 0.632, 0.620, and 0.569, respectively. Binary logistic regression analysis determined that peri-stent FAI was uniquely and independently associated with ISR after adjusting for other risk factors (odds ratio [OR] 1.403; 95% CI: 1.211 to 1.625; p < 0.001). In the subgroup analysis, the AUCs of the left anterior descending coronary artery (LAD), left circumflex coronary artery (LCx), and right coronary artery (RCA) stents groups were 0.80, 0.87, and 0.96, respectively. The Pearson's correlation coefficient indicated a term moderately correlation between ISR severity and peri-stent FAI values (r = 0.579, P < 0.001).

Conclusions

The peri-stent FAI can be used as an independently non-invasive biomarker to predict ISR risk and severity after stent implantation.

Degradation behaviors and in-vivo biocompatibility of a rare earth- and aluminum-free magnesium-based stent

Biodegradable stents can provide scaffolding and anti-restenosis benefits in the short term and then gradually disappear over time to free the vessel, among which the Mg-based biodegradable metal stents have been prosperously developed. In the present study, a Mg-8.5Li (wt.%) alloy (RE- and Al-free) with high ductility (> 40%) was processed into mini-tubes, and further fabricated into finished stent through laser cutting and electropolishing. In-vitro degradation test was performed to evaluate the durability of this stent before and after balloon dilation. The influence of plastic deformation and residual stress (derived from the dilation process) on the degradation was checked with the assistance of finite element analysis. In addition, in-vivo degradation behaviors and biocompatibility of the stent were evaluated by performing implantation in iliac artery of minipigs. The balloon dilation process did not lead to deteriorated degradation, and this stent exhibited a decent degradation rate (0.15 mm/y) in vitro, but divergent result (> 0.6 mm/y) was found in vivo. The stent was almost completely degraded in 3 months, revealing an insufficient scaffolding time. Meanwhile, it did not induce possible thrombus, and it was tolerable by surrounding tissues in pigs. Besides, endothelial coverage in 1 month was achieved even under the severe degradation condition. In the end, the feasibility of this stent for treatment of benign vascular stenosis was generally discussed, and perspectives on future improvement of Mg-Li-based stents were proposed.

Antithrombotic treatment in patients with atrial fibrillation undergoing coronary angioplasty: rational convincement and supporting evidence

BACKGROUND

The management of antithrombotic therapy in patients undergoing percutaneous coronary intervention (PCI) with an indication for long-term oral anticoagulant therapy (OAT) is still a matter of debate. We aim to evaluate the safety and the efficacy of dual therapy (DT) compared to triple therapy (TT) in this clinical setting.

METHODS

A study level meta-analysis and a review of randomized trials selected using PubMed, Embase, EBSCO, Cochrane database of systematic reviews, Web of Science, and abstract from major cardiology congresses. Six randomized trials with 12,156 patients evaluating the strategy of DT vs. TT in patients treated with PCI with indication for long-term OAT were included.

RESULTS

Patients treated with DT demonstrated a 45% relative reduction in the risk of TIMI major bleeding (1.71% vs. 2.99%; OR 0.55, 95% CI 0.41-0.71; P<0.0001) and TIMI minor bleeding compared to TT arm (4.67% vs 7.83%, OR 0.55 95% CI 0.39-0.78, P = 0.0007). All-cause mortality was similar in two arms (3.95% vs 3.77%, P = 0.92), as well as cardiovascular mortality (2.21% vs 2.19%, P = 0.97). DT was associated with a borderline increase of ST (1.02% vs 0.67%, P = 0.07). No significant differences were observed in occurrence of MI and stroke.

CONCLUSIONS

Our findings suggest that DT is safer than TT with regard to occurrence of major bleeding. DT with a direct oral anticoagulant plus clopidogrel at discharge could be effective in most patients, maintaining aspirin in periprocedural phase and as longer "tailored" treatment for patients at higher ischemic risk.

Rivaroxaban Plus Aspirin Versus Aspirin Alone in Patients With Prior Percutaneous Coronary Intervention (COMPASS-PCI)

Background:

The COMPASS trial (Cardiovascular Outcomes for People using Anticoagulation Strategies) demonstrated that dual pathway inhibition (DPI) with rivaroxaban 2.5 mg twice daily plus aspirin 100 mg once daily versus aspirin 100 mg once daily reduced the primary major adverse cardiovascular event (MACE) outcome of cardiovascular death, myocardial infarction, or stroke, as well as, mortality, in patients with chronic coronary syndromes or peripheral arterial disease. Whether this remains true in patients with a history of percutaneous coronary intervention (PCI) is unknown.

Methods:

In a prespecified subgroup analysis from COMPASS, we examined the outcomes of patients with a chronic coronary syndrome with or without a previous PCI treated with DPI versus aspirin alone. Among patients with a previous PCI, we studied the effects of treatment according to the timing of the previous PCI.

Results:

Of the 27 395 patients in COMPASS, 16 560 patients with a chronic coronary syndrome were randomly assigned to DPI or aspirin, and, of these, 9862 (59.6%) had previous PCI (mean age 68.2±7.8, female 19.4%, diabetes mellitus 35.7%, previous myocardial infarction 74.8%, multivessel PCI 38.0%). Average time from PCI to randomization was 5.4 years (SD, 4.4) and follow-up was 1.98 (SD, 0.72) years. Regardless of previous PCI, DPI versus aspirin produced consistent reductions in MACE (PCI: 4.0% versus 5.5%; hazard ratio [HR], 0.74 [95% CI, 0.61–0.88]; no PCI: 4.4% versus 5.7%; HR, 0.76 [95% CI, 0.61–0.94], P -interaction=0.85) and mortality (PCI: 2.5% versus 3.5%; HR, 0.73 [95% CI, 0.58–0.92]; no PCI: 4.1% versus 5.0%; HR, 0.80 [95% CI, 0.64–1.00], P -interaction=0.59), but increased major bleeding (PCI: 3.3% versus 2.0%; HR, 1.72 [95% CI, 1.34–2.21]; no PCI: 2.9% versus 1.8%; HR, 1.58 [95% CI, 1.15–2.17], P -interaction=0.68). In those with previous PCI, DPI compared with aspirin produced consistent (robust) reductions in MACE irrespective of time since previous PCI (as early as 1 year and as far as 10 years; P -interaction=0.65), irrespective of having a previous myocardial infarction ( P -interaction=0.64).

Conclusions:

DPI compared with aspirin produced consistent reductions in MACE and mortality but with increased major bleeding with or without previous PCI. Among those with previous PCI 1 year and beyond, the effects on MACE and mortality were consistent irrespective of time since last PCI.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01776424.

Clinical utility of intravascular ultrasonography-guided therapy in a small-vessel coronary lesion associated with Type 2 diabetes mellitus

Objective:

It is unknown whether the intravascular ultrasound (IVUS) guidance for percutaneous coronary intervention (PCI) should be routinely used in small-vessel coronary lesions in patients affected by Type 2 diabetes mellitus (T2DM). This study aimed to assess the clinical significance of the IVUS-guided PCI treatment for small-vessel coronary lesions in T2DM.

Methods:

This was a prospective interventional trial. A total of 228 patients affected by T2DM with stable angina and a positive stress test in the presence of coronary arteriography (CAG) involving small vessels [online measurement reference vessel diameter ≤3.0 mm by means of quantitative coronary angiography (QCA)] were recruited and divided into two groups: an IVUS-guided group (n=120) and a CAG-guided group (n=108). Follow-up PCIs were performed via CAG or IVUS criteria, respectively. Between-group comparisons were made for the number of stents implanted, length, diameter, and high-pressure balloons used post-dilatation. Major adverse cardiac events (MACEs) defined as cardiac death, nonfatal myocardial infarction, and target lesion revascularization (TLR) were the primary endpoint. The value of late lumen loss and proportion of in-stent restenosis (ISR) were the secondary endpoint, all of which were also evaluated during the follow-up period.

Results:

There was an increased lesion length observed using the IVUS measurement when compared with QCA measurements in the IVUS-guided group (p≤0.001). The number of implanted stents, diameter, length, percentage of high-pressure balloons used during post-dilatation, value of late lumen loss, and proportion of ISR decreased in the IVUS-guided group when compared with the CAG-guided group (p=0.002, p=0.001, p=0.003, p=0.004, p=0.007, p=0.001, respectively). After a 2-year follow-up, the Kaplan–Meier curves indicated that the incidence of MACEs was significantly lower in the IVUS-guided group (log-rank p=0.029), mainly because of the TLR reduction (log-rank p=0.037).

Conclusion:

The IVUS-guided PCI treatment improved the event-free survival in small-vessel coronary lesions in patients affected by T2DM.

Ticagrelor in patients with diabetes and stable coronary artery disease with a history of previous percutaneous coronary intervention (THEMIS-PCI): a phase 3, placebo-controlled, randomised trial

BACKGROUND

Patients with stable coronary artery disease and diabetes with previous percutaneous coronary intervention (PCI), particularly those with previous stenting, are at high risk of ischaemic events. These patients are generally treated with aspirin. In this trial, we aimed to investigate if these patients would benefit from treatment with aspirin plus ticagrelor.

METHODS

The Effect of Ticagrelor on Health Outcomes in diabEtes Mellitus patients Intervention Study (THEMIS) was a phase 3 randomised, double-blinded, placebo-controlled trial, done in 1315 sites in 42 countries. Patients were eligible if 50 years or older, with type 2 diabetes, receiving anti-hyperglycaemic drugs for at least 6 months, with stable coronary artery disease, and one of three other mutually non-exclusive criteria: a history of previous PCI or of coronary artery bypass grafting, or documentation of angiographic stenosis of 50% or more in at least one coronary artery. Eligible patients were randomly assigned (1:1) to either ticagrelor or placebo, by use of an interactive voice-response or web-response system. The THEMIS-PCI trial comprised a prespecified subgroup of patients with previous PCI. The primary efficacy outcome was a composite of cardiovascular death, myocardial infarction, or stroke (measured in the intention-to-treat population).

FINDINGS

Between Feb 17, 2014, and May 24, 2016, 11 154 patients (58% of the overall THEMIS trial) with a history of previous PCI were enrolled in the THEMIS-PCI trial. Median follow-up was 3·3 years (IQR 2·8-3·8). In the previous PCI group, fewer patients receiving ticagrelor had a primary efficacy outcome event than in the placebo group (404 [7·3%] of 5558 vs 480 [8·6%] of 5596; HR 0·85 [95% CI 0·74-0·97], p=0·013). The same effect was not observed in patients without PCI (p=0·76, p_interaction=0·16). The proportion of patients with cardiovascular death was similar in both treatment groups (174 [3·1%] with ticagrelor vs 183 (3·3%) with placebo; HR 0·96 [95% CI 0·78-1·18], p=0·68), as well as all-cause death (282 [5·1%] vs 323 [5·8%]; 0·88 [0·75-1·03], p=0·11). TIMI major bleeding occurred in 111 (2·0%) of 5536 patients receiving ticagrelor and 62 (1·1%) of 5564 patients receiving placebo (HR 2·03 [95% CI 1·48-2·76], p<0·0001), and fatal bleeding in 6 (0·1%) of 5536 patients with ticagrelor and 6 (0·1%) of 5564 with placebo (1·13 [0·36-3·50], p=0·83). Intracranial haemorrhage occurred in 33 (0·6%) and 31 (0·6%) patients (1·21 [0·74-1·97], p=0·45). Ticagrelor improved net clinical benefit: 519/5558 (9·3%) versus 617/5596 (11·0%), HR=0·85, 95% CI 0·75-0·95, p=0·005, in contrast to patients without PCI where it did not, p_interaction=0·012. Benefit was present irrespective of time from most recent PCI.

INTERPRETATION

In patients with diabetes, stable coronary artery disease, and previous PCI, ticagrelor added to aspirin reduced cardiovascular death, myocardial infarction, and stroke, although with increased major bleeding. In that large, easily identified population, ticagrelor provided a favourable net clinical benefit (more than in patients without history of PCI). This effect shows that long-term therapy with ticagrelor in addition to aspirin should be considered in patients with diabetes and a history of PCI who have tolerated antiplatelet therapy, have high ischaemic risk, and low bleeding risk.

FUNDING

AstraZeneca.

Coronary Bypass Versus Percutaneous Revascularization in Multivessel Coronary Artery Disease

BACKGROUND

This study focused on contemporary outcomes after coronary artery bypass graft (CABG) surgery versus percutaneous coronary intervention (PCI) in patients with multivessel coronary artery disease (MVCAD).

METHODS

This was a propensity-matched retrospective, observational analysis. Patients with MVCAD who underwent CABG or PCI between 2010 and 2018 and for whom data were available through the National Cardiovascular Data Registry or The Society of Thoracic Surgeons Adult Cardiac Surgery Database were included. The primary outcome was overall survival. Secondary outcomes included freedom from inpatient readmission and freedom from repeat revascularization.

RESULTS

Of the initial 6,163 patients with MVCAD, the propensity-matched cohort included 844 in each group. The estimated 1-year mortality was 11.5% and 7.2% (p < 0.001) in the PCI and CABG groups, respectively, with an overall hazard ratio for mortality of PCI versus CABG of 1.64 (95% confidence interval [CI], 1.29 to 2.10; p < 0.001). The overall hazard ratio for readmission for PCI versus CABG was 1.42 (95% CI, 1.23 to 1.64; p < 0.001). The overall hazard ratio for repeat revascularization for PCI versus CABG was 4.06 (95% CI, 2.39 to 6.91; p < 0.001). Overall major adverse cardiovascular events and individual outcomes of mortality, readmission, and repeat revascularization all favored CABG across virtually all major clinical subgroups.

CONCLUSIONS

This contemporary propensity-matched analysis of patients undergoing coronary revascularization for MVCAD demonstrates a significant mortality benefit with CABG over PCI, and this benefit is consistent across virtually all major patient subgroups. Futures studies are needed reflecting routine practice to assess how best to approach shared decision making and informed consent when it comes to revascularization decisions in any patient with MVCAD.

Drug-Eluting Versus Bare-Metal Stents in Older Patients: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Despite the high prevalence of ischemic heart disease in older patients, there is a substantial lack of evidence to guide clinical decision-making in this population. Hence, we performed a meta-analysis to determine the safety and efficacy of percutaneous coronary intervention (PCI) with drug-eluting stents (DES) versus bare-metal stents (BMS).

METHODS

Electronic databases were searched for randomized trials comparing DES with BMS in patients ≥70 years-old. The primary outcome was major adverse cardiovascular events (MACE). Secondary outcomes included different ischemic and bleeding events. Subgroup analyses for dual-antiplatelet therapy (DAPT) duration were conducted.

RESULTS

We included 7 trials with a total of 5449 patients. The use of DES compared with BMS was associated with a significant reduction in MACE (odds ratio [OR]:0.76; 95% confidence interval [CI]:0.62-0.93; P = 0.007) with no increased risk of bleeding events (OR: 1.07; 95% CI: 0.89-1.27; P = 0.48). However, longer duration of DAPT (>6 months) for the DES group increased bleeding events (OR: 1.52; 95% CI: 1.05-2.20; P = 0.03). In contrast, shorter DAPT showed persistent efficacy in reducing MACE in DES-treated patients with no increased bleeding events (OR: 0.72; 95% CI: 0.60-0.87; P < 0.01 and OR: 1.01; 95% CI: 0.84-1.22; P = 0.89, respectively).

CONCLUSIONS

In older patients who had undergone PCI, DES showed superior efficacy in reducing MACE with no increased risk of bleeding compared with BMS. Persistent MACE reduction was evident with shorter DAPT durations in DES-treated patients.

SUMMARY

This meta-analysis of randomized clinical trials demonstrated that drug-eluting stents were associated with a significant reduction in major adverse cardiovascular events with no increased risk of bleeding compared with bare-metal stents. The risk of bleeding was high with longer dual antiplatelet therapy duration for patients who underwent DES placement. However, short duration of dual antiplatelet therapy substantially reduced major adverse cardiovascular events with no increased bleeding risk.

Management of Anticoagulation in Patients with Atrial Fibrillation Undergoing PCI: Double or Triple Therapy?

PURPOSE OF REVIEW

This review aims to discuss the use of antithrombotic therapy in patients with atrial fibrillation who undergo coronary stenting with emphasis on the use of double vs triple therapy.

RECENT FINDINGS

When combined with systemic anticoagulation, dual antiplatelet therapy results in an unacceptable increase in bleeding without any improvement in prevention of thrombotic events. Direct oral anticoagulants combined with single antiplatelet therapy have reduced bleeding compared with warfarin plus dual antiplatelet therapy. Triple anticoagulation therapy with warfarin or direct oral anticoagulants leads to an excess of bleeding and is not superior in preventing thrombotic events. Recent randomized, controlled trials have shown a significant reduction in major bleeding events in patients treated with dual antithrombotic therapy compared with triple therapy without any difference in efficacy. These findings call into question whether triple therapy should remain a part of standard practice.

Dual versus triple therapy in patients on oral anticoagulants and undergoing coronary stent implantation: A systematic review and meta-analysis

BACKGROUND AND AIMS

There is contrasting evidence regarding the optimal antithrombotic regimen after percutaneous coronary stent implantation in patients on oral anticoagulants. A systematic review and meta-analysis was performed to explore the comparative efficacy and safety of dual (an antiplatelet plus an oral anticoagulant) versus triple therapy (dual antiplatelet therapy plus an oral anticoagulant).

METHODS

We searched the literature for randomized controlled trials (RCTs) or observational studies (OSs) addressing this issue. The efficacy outcomes were all-cause mortality, cardiovascular mortality, myocardial infarction and stent thrombosis. The safety outcomes were major bleeding events and all bleeding events. The analyses were stratified by type of anticoagulant and of antiplatelet used in dual therapy.

RESULTS

Four RCTs and ten OSs met our inclusion criteria including a total of 10,126 patients. 5671 patients received triple therapy whereas 4455 received dual therapy. Median follow up was 12 months. There was no difference between dual therapy and triple therapy regarding efficacy outcomes. Dual therapy significantly reduced the risk of major bleeding (RR 0.66; CI 95% 0.52-0.83; P = 0.0005) and of all bleeding events (RR 0.67, CI 95% 0.55-0.80; P < 0.0001). The effect was consistent regardless of the type of antiplatelet and anticoagulant used in dual therapy.

CONCLUSION

Dual antithrombotic therapy after coronary stenting in anticoagulated patients significantly reduces bleeding events compared with triple therapy. Dual therapy might be considered in this setting especially when bleeding risk outweighs ischemic risk, although our study was not sufficiently powered to detect a difference in ischemic endpoints.

Intravascular Ultrasound for Guidance and Optimization of Percutaneous Coronary Intervention

Percutaneous coronary intervention (PCI) remains the mainstay management of symptomatic obstructive stable coronary artery disease (despite optimal medical treatment) and acute coronary syndrome. Intravascular ultrasound (IVUS) has emerged as an adjunct to angiography, permitting better assessment of the coronary lesion and stent apposition. Data from multiple studies have demonstrated improved clinical and procedural outcomes with IVUS-guided PCI. This review discusses the use of IVUS, with emphasis on technique, parameters, and applications during coronary interventions. In addition, the clinical outcomes data are highlighted with IVUS compared with conventional angiography-guided PCI.

Endothelial cell activation is attenuated by everolimus via transcriptional and post-transcriptional regulatory mechanisms after drug-eluting coronary stenting

We previously found higher level of endothelial cell (EC) activation in patients who suffered from in-stent restenosis after bare-metal stenting compared to subjects who underwent drug-eluting stenting (DES) showing no complications. Here we investigated the potential transcriptional and post-transcriptional regulatory mechanisms by which everolimus attenuated EC activation after DES. We studied the effect of everolimus on E-selectin (SELE) and VCAM1 mRNA levels when human coronary artery (HCAECs) and human umbilical vein ECs were challenged with recombinant TNF-α (100 ng/mL) for 1–24 hours in the presence or absence of everolimus using 0.5 μM concentration locally maintained by DES. EC activation was evaluated via the levels of IL-1β and IL-6 mRNAs with miR-155 expression by RT-qPCR as well as the nuclear translocation of nuclear factor kappa beta (NF-κB) detected by fluorescence microscopy. To investigate the transcriptional regulation of E-selectin and VCAM-1, TNF-α-induced enhancer RNA (eRNA) expression at p65-bound enhancers in the neighboring genomic regions of SELE and VCAM1 genes, including SELE_-11Kb and VCAM1_-10Kb, were measured in HCAECs. Mature and precursor levels of E-selectin and VCAM-1 repressor miR-181b were quantified to analyze the post-transcriptional regulation of these genes in HCAECs. Circulating miR-181b was analyzed in plasma samples of stented subjects by stem-loop RT-qPCR. TNF-α highly elevated E-selectin and VCAM-1 expression at transcriptional level in ECs. Levels of mature, pre- and pri-miR-181b were repressed in ECs by TNF-α, while everolimus acted as a negative regulator of EC activation via inhibited translocation of NF-κB p65 subunit into cell nuclei, lowered eRNA expression at SELE and VCAM1 genes-associated enhancers and modulated expression of their post-transcriptional repressor miR-181b. Significant negative correlation was observed between plasma miR-181b and soluble E-selectin and VCAM-1 in patients. In conclusion, everolimus attenuates EC activation via reduced NF-κB p65 translocation causing decreased E-selectin and VCAM-1 expression at transcriptional and post-transcriptional level after DES.

Safety and efficacy of dual vs. triple antithrombotic therapy in patients with atrial fibrillation following percutaneous coronary intervention: a systematic review and meta-analysis of randomized clinical trials

Aims

Of patients with atrial fibrillation (AF), approximately 10% undergo percutaneous coronary intervention (PCI). We studied the safety and efficacy of dual vs. triple antithrombotic therapy (DAT vs. TAT) in this population.

Methods and results

A systematic review and meta-analysis was conducted using PubMed, Embase, EBSCO, Cochrane database of systematic reviews, Web of Science, and relevant meeting abstracts for Phase 3, randomized trials that compared DAT vs. TAT in patients with AF following PCI. Four trials including 5317 patients were included, of whom 3039 (57%) received DAT. Compared with the TAT arm, Thrombolysis in Myocardial Infarction (TIMI) major or minor bleeding showed a reduction by 47% in the DAT arm [4.3% vs. 9.0%; hazard ratio (HR) 0.53, 95% credible interval (CrI) 0.36-0.85, I2 = 42.9%]. In addition, there was no difference in the trial-defined major adverse cardiac events (MACE) (10.4% vs. 10.0%, HR 0.85, 95% CrI 0.48-1.29, I2 = 58.4%), or in individual outcomes of all-cause mortality, cardiac death, myocardial infarction, stent thrombosis, or stroke between the two arms.

Conclusion

Compared with TAT, DAT shows a reduction in TIMI major or minor bleeding by 47% with comparable outcomes of MACE. Our findings support the concept that DAT may be a better option than TAT in many patients with AF following PCI.

Reproducible Arterial Denudation Injury by Infrarenal Abdominal Aortic Clamping in a Murine Model

Percutaneous vascular interventions uniformly result in arterial denudation injuries that subsequently lead to thrombosis and restenosis. These complications can be attributed to impairments in re-endothelialization within the wound margins. Yet, the cellular and molecular mechanisms of re-endothelialization remain to be defined. While several animal models to study re-endothelialization after arterial denudation are available, few are performed in the mouse because of surgical limitations. This undermines the opportunity to exploit transgenic mouse lines and investigate the contribution of specific genes to the process of re-endothelialization. Here, we present a step-by-step protocol for creating a highly reproducible murine model of arterial denudation injury in the infrarenal abdominal aorta using external vascular clamping. Immunocytochemical staining of injured aortas for fibrinogen and β-catenin demonstrate the exposure of a pro-thrombotic surface and the border of intact endothelium, respectively. The method presented here has the advantages of speed, excellent overall survival rate, and relative technical ease, creating a uniquely practical tool for imposing arterial denudation injury in transgenic mouse models. Using this method, investigators may elucidate the mechanisms of re-endothelialization under normal or pathological conditions.

Reducing In-Stent Restenosis: Therapeutic Manipulation of miRNA in Vascular Remodeling and Inflammation

Background

Drug-eluting stents reduce the incidence of in-stent restenosis, but they result in delayed arterial healing and are associated with a chronic inflammatory response and hypersensitivity reactions. Identifying novel interventions to enhance wound healing and reduce the inflammatory response may improve long-term clinical outcomes. Micro–ribonucleic acids (miRNAs) are noncoding small ribonucleic acids that play a prominent role in the initiation and resolution of inflammation after vascular injury.

Objectives

This study sought to identify miRNA regulation and function after implantation of bare-metal and drug-eluting stents.

Methods

Pig, mouse, and in vitro models were used to investigate the role of miRNA in in-stent restenosis.

Results

We documented a subset of inflammatory miRNAs activated after stenting in pigs, including the miR-21 stem loop miRNAs. Genetic ablation of the miR-21 stem loop attenuated neointimal formation in mice post-stenting. This occurred via enhanced levels of anti-inflammatory M2 macrophages coupled with an impaired sensitivity of smooth muscle cells to respond to vascular activation.

Conclusions

MiR-21 plays a prominent role in promoting vascular inflammation and remodeling after stent injury. MiRNA-mediated modulation of the inflammatory response post-stenting may have therapeutic potential to accelerate wound healing and enhance the clinical efficacy of stenting.

Healing arterial ulcers: Endothelial lining regeneration upon vascular denudation injury

Thrombosis and restenosis are the most prevalent late complications of coronary artery stenting. Current standards of clinical care focus on prevention of smooth muscle cell proliferation by the use of drug-eluting stents able to release anti-proliferative drugs. Unfortunately, these drugs also block endothelial cell proliferation and, in this manner, prevent recovery of endothelial cell coverage. Continued lack of endothelial repair leaves the root cause of thrombosis and restenosis unchanged, creating a vicious cycle where drug-mediated prevention of restenosis simultaneously implies promotion of thrombosis. In this issue of Vascular Pharmacology, Hussner and colleagues provide in vitro evidence and a mechanistic basis for the use of atorvastatin in stents as a way to bypass this roadblock. Here we review the pathological mechanisms and therapeutic approaches to restore flow in occluded arteries. We argue that rational design of drug eluting stents should focus on specific inhibition of smooth muscle cell proliferation with concurrent stimulation of endothelial regeneration. We comment on the current poor understanding of the cellular and molecular regulation of endothelial cell proliferation in the context of a functional artery, and on the pitfalls of extrapolating from the well-studied process of neovascularization by sprouting vessel formation.

Complete versus culprit-only revascularization in patients with multi-vessel disease undergoing primary percutaneous coronary intervention: A meta-analysis of randomized trials

BACKGROUND

The best approach for revascularization of multi-vessel coronary disease in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) is controversial.

METHODS

We searched the Medline and Web of Science databases, the Cochrane Register of Controlled Trials, and major conference proceedings for clinical trials that randomized STEMI patients with multi-vessel disease to a complete versus culprit-only revascularization strategy. Random effects summary risk ratios (RR) were constructed using a DerSimonian-Laird model.

RESULTS

A total of 6 trials met our selection criteria, which yielded 1,190 patients. The mean follow-up duration was 20.5 months. The incidence of major adverse cardiac events was significantly reduced in the complete revascularization group versus the culprit-only revascularization group (RR 0.57, 95% confidence interval (CI) 0.41-0.78, p < 0.001). This was due to a lower risk of urgent revascularization with complete revascularization (RR 0.55, 95% CI 0.35-0.86, p = 0.01). A non-significant reduction was observed with complete versus culprit-only revascularization for the combined outcome of mortality or myocardial infarction (RR 0.56, 95% CI 0.30-1.04, p = 0.06).

CONCLUSION

Complete revascularization of significant coronary lesions at the time of primary PCI in patients with STEMI and multi-vessel disease was associated with better outcomes. This was primarily due to a reduction in the need for urgent revascularization. Larger trials are needed to determine if complete revascularization reduces death or myocardial infarction.

Outcomes associated with fractional flow-guided revascularization: a meta-analysis

BACKGROUND

Deferral of revascularization for abnormal but nonischemic lesions is usually recommended; however, the long-term outcome of this approach is not well known.

HYPOTHESIS

Deferral of nonischemic lesions will be associated with a low frequency of adverse events.

METHODS

A PubMed search of the MEDLINE database identified studies that reported clinical outcomes among patients who had fractional flow reserve-guided revascularization. We further categorized studies into 2 subgroups: left main and non-left main coronary artery lesions. Baseline demographics and clinical outcome data were extracted by 3 independent reviewers. Fixed and random effects summary risk ratios were constructed using Mantel-Haenszel and DerSimonian-Laird models, respectively. The primary outcome was the composite of death, myocardial infarction, and revascularization.

RESULTS

From 741 potential studies, 17 were included in the meta-analysis (n = 2975 participants), 8 in the left main subgroup (n = 595) and 9 studies (n = 2380) in non-left main subgroup. In the left main subgroup, the incidence of the composite outcome was 15.3% in the no-ischemia/deferral group vs 14.3% in the ischemia/revascularization group (risk ratio [RR] = 1.13, 95% confidence interval [CI]: 0.76-1.68, P = 0.54, I(2) = 3.7%). In the non-left main subgroup, the incidence of the composite outcome was 9.2% in the no-ischemia/deferral group vs 18.8% in the ischemia/revascularization group (RR = 0.42, 95% CI: 0.34-0.52, P < 0.0001, I(2) = 20.7%).

CONCLUSIONS

Patients with left main coronary disease had a relatively high incidence of adverse cardiovascular events, which was similar in both the deferral and revascularization groups. In patients with non-left main disease, ischemia was associated with worse outcomes despite revascularization.

Stem/Progenitor cells in vascular regeneration

A series of studies has been presented in the search for proof of circulating and resident vascular progenitor cells, which can differentiate into endothelial and smooth muscle cells and pericytes in animal and human studies. In terms of pluripotent stem cells, including embryonic stem cells, iPS, and partial-iPS cells, they display a great potential for vascular lineage differentiation. Development of stem cell therapy for treatment of vascular and ischemic diseases remains a major challenging research field. At the present, there is a clear expansion of research into mechanisms of stem cell differentiation into vascular lineages that are tested in animal models. Although there are several clinical trials ongoing that primarily focus on determining the benefits of stem cell transplantation in ischemic heart or peripheral ischemic tissues, intensive investigation for translational aspects of stem cell therapy would be needed. It is a hope that stem cell therapy for vascular diseases could be developed for clinic application in the future.

The formation of an anti-restenotic/anti-thrombotic surface by immobilization of nitric oxide synthase on a metallic carrier

Coronary stenosis due to atherosclerosis, the primary cause of coronary artery disease, is generally treated by balloon dilatation and stent implantation, which can result in damage to the endothelial lining of blood vessels. This leads to the restenosis of the lumen as a consequence of migration and proliferation of smooth muscle cells (SMCs). Nitric oxide (NO), which is produced and secreted by vascular endothelial cells (ECs), is a central anti-inflammatory and anti-atherogenic player in the vasculature. The goal of the present study was to develop an enzymatically active surface capable of converting the prodrug l-arginine, to the active drug, NO, thus providing a targeted drug delivery interface. NO synthase (NOS) was chemically immobilized on the surface of a stainless steel carrier with preservation of its activity. The ability of this functionalized NO-producing surface to prevent or delay processes involved in restenosis and thrombus formation was tested. This surface was found to significantly promote EC adhesion and proliferation while inhibiting that of SMCs. Furthermore, platelet adherence to this surface was markedly inhibited. Beyond the application considered here, this approach can be implemented for the local conversion of any systemically administered prodrug to the active drug, using catalysts attached to the surface of the implant.

What is the optimum adjunctive reperfusion strategy for primary percutaneous coronary intervention?

Acute ST-segment elevation myocardial infarction (STEMI) is a dynamic, thrombus-driven event. As understanding of its pathophysiology has improved, the central role of platelets in initiation and orchestration of this process has become clear. Key components of STEMI include formation of occlusive thrombus, mediation and ultimately amplification of the local vascular inflammatory response resulting in increased vasoreactivity, oedema formation, and microvascular obstruction. Activation, degranulation, and aggregation of platelets are the platforms from which these components develop. Therefore, prompt, potent, and predictable antithrombotic therapy is needed to optimise clinical outcomes after primary percutaneous coronary intervention. We review present pharmacological and mechanical adjunctive therapies for reperfusion and ask what is the optimum combination when primary percutaneous coronary intervention is used as the mode of revascularisation in patients with STEMI.

Impact of scheduled angiographic follow-up in patients treated with primary percutaneous coronary intervention for ST-segment elevation myocardial infarction

Routine scheduled angiographic follow-up (SAF) after percutaneous coronary intervention (PCI) has been associated with a higher rate of target vessel revascularization (TVR). Its benefits are not known. SAF at 13 months after ST-segment elevation myocardial infarction (STEMI) was planned in the first 1,800 successfully stented patients enrolled in the Harmonizing Outcomes with RevascularIZatiON and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial. We compared the outcomes of patients with and without SAF at 1 year (before SAF) and at 3 years (after SAF). There were 1,197 patients (66.5% of expected) with and 2,207 patients without SAF. Prior to SAF, the 1-year composite rate of death or myocardial infarction (MI) was not significantly different between the 2 groups (2.7% vs. 3.9%, respectively, P=0.06), although the rate of death was lower (0.1% vs. 2.2%, P<0.0001), nor were there differences in the 1-year rates of TVR, stent thrombosis or major adverse cardiac and cerebral events). At 3 years, death or MI rates were again similar between the groups (8.3% vs. 9.5%, P=0.22), but TVR was more common in the SAF group (17.0% vs. 8.6%, P<0.0001), due to an increase in TVR at time of SAF. In the SAF group, patients in whom TVR was performed before or after the 13-month SAF window had markedly higher 3-year rates of MI and stent thrombosis than patients in whom TVR was performed during SAF or not at all. In conclusion, SAF after primary PCI in STEMI is associated with doubling of the rate of revascularization without an improvement in death or MI, and therefore cannot be recommended.

Comparison of frequency of major adverse events in patients with atrial fibrillation receiving bare-metal versus drug-eluting stents in their coronary arteries

In patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention with drug-eluting stent (DES) implantation, the available evidence from clinical trial data are inconclusive. We evaluated the safety and efficacy of the use of DESs versus bare-metal stents (BMSs) in a consecutive real-world cohort of patients with AF. Of 8,962 unselected patients with AF seen in our institution from 2000 through 2010, 833 (9%) had undergone percutaneous coronary intervention with stent implantation. BMSs were used for 678 patients (81%) and DESs for 155 (19%). During follow-up (median 688 days, interquartile range 1,114), all bleeding episodes, thromboembolism, and major adverse cardiac events (MACEs; i.e., death, acute myocardial infarction, target lesion revascularization) were recorded. Incidence of MACEs was similar in the 2 groups as was incidence of all-cause mortality. Results remained similar even after adjustment for age and other confounding factors. Factors independently associated with an increased risk of MACEs were older age (hazard ratio 1.024, 95% confidence interval 1.004 to 1.044, p = 0.02), implantation of stent during acute ST-segment elevation myocardial infarction (hazard ratio 1.81, 95% confidence interval 1.10 to 2.99, p = 0.02), and stent diameter (hazard ratio 1.09, 95% confidence interval 1.01 to 1.18, p = 0.03). Implantation of DESs was not significantly associated with a higher risk of major bleeding and we observed a similar ratio of serious events at follow-up after DES compared to BMS implantation. In conclusion, in our cohort, systematic use of DESs does not seem to be justified in most patients with AF because it was not associated with any clear advantage compared to BMSs.

Contribution of stem cells to neointimal formation of decellularized vessel grafts in a novel mouse model

Artificial vessel grafts are often used for the treatment of occluded blood vessels, but neointimal lesions commonly occur. To both elucidate and quantify which cell types contribute to the developing neointima, we established a novel mouse model of restenosis by grafting a decellularized vessel to the carotid artery. Typically, the graft developed neointimal lesions after 2 weeks, resulting in lumen closure within 4 weeks. Immunohistochemical staining revealed the presence of endothelial and smooth muscle cells, monocytes, and stem/progenitor cells at 2 weeks after implantation. Explanted cultures of neointimal tissues displayed heterogeneous outgrowth in stem cell medium. These lesional cells expressed a panel of stem/progenitor markers, including c-kit, stem cell antigen-1 (Sca-1), and CD34. Furthermore, these cells showed clonogenic and multilineage differentiation capacities. Isolated Sca-1(+) cells were able to differentiate into endothelial and smooth muscle cells in response to vascular endothelial growth factor (VEGF) or platelet-derived growth factor (PDGF)-BB stimulation in vitro. In vivo, local application of VEGF to the adventitial side of the decellularized vessel increased re-endothelialization and reduced neointimal formation in samples at 4 weeks after implantation. A population of stem/progenitor cells exists within developing neointima, which displays the ability to differentiate into both endothelial and smooth muscle cells and can contribute to restenosis. Our findings also indicate that drugs or cytokines that direct cell differentiation toward an endothelial lineage may be effective tools in the prevention or delay of restenosis.

Short- and long-term outcomes with drug-eluting and bare-metal coronary stents: a mixed-treatment comparison analysis of 117 762 patient-years of follow-up from randomized trials

BACKGROUND

Drug-eluting stents (DES) have been in clinical use for nearly a decade; however, the relative short- and long-term efficacy and safety of DES compared with bare-metal stents (BMS) and among the DES types are less well defined.

METHODS AND RESULTS

PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for randomized clinical trials, until March 2012, that compared any of the Food and Drug Administration-approved durable stent and polymer DES (sirolimus-eluting stent [SES], paclitaxel-eluting stent [PES], everolimus-eluting stent [EES], zotarolimus-eluting stent [ZES], and ZES-Resolute [ZES-R]) with each other or against BMS for de novo coronary lesions, enrolling at least 100 patients and with follow-up of at least 6 months. Short-term (≤ 1 year) and long-term efficacy (target-vessel revascularization, target-lesion revascularization) and safety (death, myocardial infarction, stent thrombosis) outcomes were evaluated and trial-level data pooled by both mixed-treatment comparison and direct comparison analyses. From 76 randomized clinical trials with 117 762 patient-years of follow-up, compared with BMS, each DES reduced long-term target-vessel revascularization (39%-61%), but the magnitude varied by DES type (EES~SES~ZES-R>PES~ZES>BMS), with a >42% probability that EES had the lowest target-vessel revascularization rate. There was no increase in the risk of any long-term safety outcomes, including stent thrombosis, with any DES (versus BMS). In addition, there was reduction in myocardial infarction (all DES except PES versus BMS) and stent thrombosis (with EES versus BMS: Rate ratio, 0.51; 95% credibility interval, 0.35-0.73). The safest DES appeared to be EES (>86% probability), with reduction in myocardial infarction and stent thrombosis compared with BMS. Short-term outcomes were similar to long-term outcomes, with SES, ZES-R, and everolimus-eluting stent being the most efficacious and EES being the safest stent.

CONCLUSIONS

DES are highly efficacious at reducing the risk of target-vessel revascularization without an increase in any safety outcomes, including stent thrombosis. However, among the DES types, there were considerable differences, such that EES, SES, and ZES-R were the most efficacious and EES was the safest stent.

Outcome of percutaneous coronary intervention utilizing drug-eluting stents in patients with reduced left ventricular ejection fraction

Ischemic cardiomyopathy with depressed left ventricular ejection fraction (LVEF) is predictive of death after percutaneous coronary intervention (PCI), but its association with stent thrombosis (ST) and the need for repeat revascularization is less clearly defined. In total 5,377 patients undergoing PCI were retrospectively evaluated. Multivariable Cox proportional hazards regression and competitive outcome analysis were employed. The primary end point was 1-year major adverse cardiac events (all-cause death, Q-wave myocardial infarction, ST, and target lesion revascularization [TLR]). Individual end points of ST and of TLR were also evaluated. Patients with normal LVEF (>50%) were compared to those with mild (41% to 50%), moderate (25% to 40%), and severe (<25%) decreases in LVEF. Patients with abnormal LVEF were older and more commonly diabetic and had renal insufficiency and heart failure syndrome (p <0.001 for all variables). These patients demonstrated more angiographically complex lesions and less frequently received a drug-eluting stent. The primary end point was significantly increased in patients with lower LVEF (9.7% for normal LVEF vs 20.6% for severely decreased LVEF, p <0.001). ST occurred more frequently in these patients (1.4% for normal LVEF vs 6% for severely decreased LVEF, p <0.001), but clinically driven TLR did not significantly change across LVEF categories. After adjustment, only moderate and severe LVEF decreases (i.e., LVEF ≤40%) demonstrated an association with major adverse cardiac events and with the individual outcome of ST. Subgroup analysis of patients receiving only a drug-eluting stent or a bare-metal stent demonstrated no statistically significant differences for the probability of ST. In conclusion, decreased LVEF is not associated with clinically driven TLR but does increase the risk of ST. Patients with LVEF ≤40% appear to be at significantly higher risk for ST and therefore might benefit from interventional and pharmacologic strategies aimed at minimizing this risk.

Platelet adenosine diphosphate receptor antagonists: ticlopidine to ticagrelor-a long continuing journey

Platelet aggregation plays a central role in the pathogenesis of atherothrombosis. Platelet adenosine diphosphate (ADP) receptor antagonists (ticlopidine, clopidogrel, prasugrel, and ticagrelor) are a major advance in the treatment of atherothrombotic diseases, especially acute coronary syndromes (ACS). Ticlopidine was the first thienopyridine introduced into clinical practice, but its potentially serious haematological side-effects limited its use and it was quickly eclipsed by clopidogrel. Clinical trials established aspirin plus clopidogrel as the standard dual anti-platelet therapy in patients with ACS and patients undergoing percutaneous coronary intervention (PCI) with stenting. Clopidogrel was found to have pharmacokinetic and pharmacodynamic limitations. Prasugrel is the next approved thienopyridine that has shown superior efficacy in ACS patients undergoing PCI in comparison to clopidogrel, although at the cost of a higher bleeding risk. Ticagrelor is the latest non-thienopyridine ADP receptor blocker that is potent, effective, reversible, and relatively safer as compared to clopidogrel. Both prasugrel and ticagrelor are more potent than clopidogrel. The data so far suggests that ticagrelor has a wider applicability in usage in patients with ACS as compared to prasugrel. Prasugrel however seems to be better tolerated. Search is on for newer more potent but safer anti-platelet agents.

Impact of main branch stenting on endothelial shear stress: role of side branch diameter, angle and lesion

In-stent restenosis and stent thrombosis remain clinically significant problems for bifurcation lesions. The objective of this study is to determine the haemodynamic effect of the side branch (SB) on main branch (MB) stenting. We hypothesize that the presence of a SB has a negative effect on MB wall shear stress (WSS), wall shear stress gradient (WSSG) and oscillatory shear index (OSI); and that the bifurcation diameter ratio (SB diameter/MB diameter) and angle are important contributors. We further hypothesized that stent undersizing exaggerates the negative effects on WSS, WSSG and OSI. To test these hypotheses, we developed computational models of stents and non-Newtonian blood. The models were then interfaced, meshed and solved in a validated finite-element package. Stents at bifurcation models were created with 30° and 70° bifurcation angles and bifurcations with diameter ratios of SB/MB = 1/2 and 3/4. It was found that stents placed in the MB at a bifurcation lowered WSS dramatically, while elevating WSSG and OSI. Undersizing the stent exaggerated the decrease in WSS, increase in WSSG and OSI, and disturbed the flow between the struts and the vessel wall. Stenting the MB at bifurcations with larger SB/MB ratios or smaller SB angles (30°) resulted in lower WSS, higher WSSG and OSI. Stenosis at the SB lowered WSS and elevated WSSG and OSI. These findings highlight the effects of major biomechanical factors in MB stenting on endothelial WSS, WSSG, OSI and suggests potential mechanisms for the potentially higher adverse clinical events associated with bifurcation stenting.

Mis-sizing of stent promotes intimal hyperplasia: impact of endothelial shear and intramural stress

Stent can cause flow disturbances on the endothelium and compliance mismatch and increased stress on the vessel wall. These effects can cause low wall shear stress (WSS), high wall shear stress gradient (WSSG), oscillatory shear index (OSI), and circumferential wall stress (CWS), which may promote neointimal hyperplasia (IH). The hypothesis is that stent-induced abnormal fluid and solid mechanics contribute to IH. To vary the range of WSS, WSSG, OSI, and CWS, we intentionally mismatched the size of stents to that of the vessel lumen. Stents were implanted in coronary arteries of 10 swine. Intravascular ultrasound (IVUS) was used to size the coronary arteries and stents. After 4 wk of stent implantation, IVUS was performed again to determine the extent of IH. In conjunction, computational models of actual stents, the artery, and non-Newtonian blood were created in a computer simulation to yield the distribution of WSS, WSSG, OSI, and CWS in the stented vessel wall. An inverse relation (R(2) = 0.59, P < 0.005) between WSS and IH was found based on a linear regression analysis. Linear relations between WSSG, OSI, and IH were observed (R(2) = 0.48 and 0.50, respectively, P < 0.005). A linear relation (R(2) = 0.58, P < 0.005) between CWS and IH was also found. More statistically significant linear relations between the ratio of CWS to WSS (CWS/WSS), the products CWS × WSSG and CWS × OSI, and IH were observed (R(2) = 0.67, 0.54, and 0.56, respectively, P < 0.005), suggesting that both fluid and solid mechanics influence the extent of IH. Stents create endothelial flow disturbances and intramural wall stress concentrations, which correlate with the extent of IH formation, and these effects were exaggerated with mismatch of stent/vessel size. These findings reveal the importance of reliable vessel and stent sizing to improve the mechanics on the vessel wall and minimize IH.

Drug-eluting stents in patients at high risk of restenosis: assessment for France

BACKGROUND

In unselected patients, the incidence of restenosis is lower after placement of drug-eluting stents (DES) than bare-metal stents (BMS) without difference in safety at a time horizon of 4 years. However, DES appears less effective in "off label" patients.

OBJECTIVES

The aim of the study was to assess available evidence of DES efficacy and safety by patient category to establish when DES placement may be recommended for reimbursement by the French national health insurance.

METHODS

Based on a systematic review by patient category (January 2002 to August 2009), two health technology assessment (HTA) reports and thirty-eight clinical studies not covered by the HTA reports (eleven meta-analysis including ours, eleven randomized trials and sixteen cohort studies) were selected. After assessment of the methodological quality, the studies mostly comparing DES with BMS were reviewed by a panel of health professionals who defined a priori the most relevant end points of safety and efficacy.

RESULTS

Seven to fourteen patients treated with DES were needed to avoid one target lesion revascularization (TLR) in patients with lesions >15 mm long, vessel diameter <3 mm, or diabetes, and with some complex lesions (total coronary occlusion, BMS in-stent restenosis multivessel disease, unprotected left main stenosis). DES appeared as safe as other alternatives over a follow-up of up to 4 years when dual antiplatelet therapy was continued for at least 1 year, but statistical power remains limited to conclude for some clinical features.

CONCLUSIONS

For reimbursement, DES use should be limited to certain categories of patients. Treatment of particular cases requires a multidisciplinary approach.

Myocardial Perfusion SPECT Imaging in Patients after Percutaneous Coronary Intervention

Coronary artery disease (CAD) is the most prevalent form of cardiovascular disease affecting about 13 million Americans, while more than one million percutaneous transluminal intervention (PCI) procedures are performed annually in the USA. The relative high occurrence of restenosis, despite stent implementation, seems to be the primary limitation of PCI. Over the last decades, single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), has proven an invaluable tool for the diagnosis of CAD and patients’ risk stratification, providing useful information regarding the decision about revascularization and is well suited to assess patients after intervention. Information gained from post-intervention MPI is crucial to differentiate patients with angina from those with exo-cardiac chest pain syndromes, to assess peri-intervention myocardial damage, to predict-detect restenosis after PCI, to detect CAD progression in non-revascularized vessels, to evaluate the effects of intervention if required for occupational reasons and to evaluate patients’ long-term prognosis. On the other hand, chest pain and exercise electrocardiography are largely unhelpful in identifying patients at risk after PCI.

Although there are enough published data demonstrating the value of myocardial perfusion SPECT imaging in patients after PCI, there is still debate on whether or not these tests should be performed routinely.